優先隊列 選擇優先度

非本人原版，出自鏈接當時忘記記了。

這串代碼對博主我幫助很大

#include<stdio.h>
#include<functional>
#include<queue>
#include<vector>
using namespace std;
//定義結構，使用運算符重載,自定義優先級1
struct cmp1{
    bool operator ()(int &a,int &b){
        return a>b;//最小值優先
    }
};
struct cmp2{
    bool operator ()(int &a,int &b){
        return a<b;//最大值優先
    }
};
//定義結構，使用運算符重載,自定義優先級2
struct number1{
    int x;
    bool operator < (const number1 &a) const {
        return x>a.x;//最小值優先
    }
};
struct number2{
    int x;
    bool operator < (const number2 &a) const {
        return x<a.x;//最大值優先
    }
};
int a[]={14,10,56,7,83,22,36,91,3,47,72,0};
number1 num1[]={14,10,56,7,83,22,36,91,3,47,72,0};
number2 num2[]={14,10,56,7,83,22,36,91,3,47,72,0};

int main()
{   priority_queue<int>que;//採用默認優先級構造隊列

    priority_queue<int,vector<int>,cmp1>que1;//最小值優先
    priority_queue<int,vector<int>,cmp2>que2;//最大值優先

    priority_queue<int,vector<int>,greater<int> >que3;//注意“>>”會被認爲錯誤，
                                                      //這是右移運算符，所以這裏用空格號隔開
    priority_queue<int,vector<int>,less<int> >que4;////最大值優先

    priority_queue<number1>que5;
    priority_queue<number2>que6;

    int i;
    for(i=0;a[i];i++){
        que.push(a[i]);
        que1.push(a[i]);
        que2.push(a[i]);
        que3.push(a[i]);
        que4.push(a[i]);
    }
    for(i=0;num1[i].x;i++)
        que5.push(num1[i]);
    for(i=0;num2[i].x;i++)
        que6.push(num2[i]);


    printf("採用默認優先關係:\n(priority_queue<int>que;)\n");
    printf("Queue 0:\n");
    while(!que.empty()){
        printf("%3d",que.top());
        que.pop();
    }
    puts("");
    puts("");

    printf("採用結構體自定義優先級方式一:\n(priority_queue<int,vector<int>,cmp>que;)\n");
    printf("Queue 1:\n");
    while(!que1.empty()){
        printf("%3d",que1.top());
        que1.pop();
    }
    puts("");
    printf("Queue 2:\n");
    while(!que2.empty()){
        printf("%3d",que2.top());
        que2.pop();
    }
    puts("");
    puts("");
    printf("採用頭文件\"functional\"內定義優先級:\n(priority_queue<int,vector<int>,greater<int>/less<int> >que;)\n");
    printf("Queue 3:\n");
    while(!que3.empty()){
        printf("%3d",que3.top());
        que3.pop();
    }
    puts("");
    printf("Queue 4:\n");
    while(!que4.empty()){
        printf("%3d",que4.top());
        que4.pop();
    }
    puts("");
    puts("");
    printf("採用結構體自定義優先級方式二:\n(priority_queue<number>que)\n");
    printf("Queue 5:\n");
    while(!que5.empty()){
        printf("%3d",que5.top());
        que5.pop();
    }
    puts("");
    printf("Queue 6:\n");
    while(!que6.empty()){
        printf("%3d",que6.top());
        que6.pop();
    }
    puts("");
    return 0;
}